Abstract: An alerting device generates a variable alert that is varied to indicate the amount of time that has elapsed since the alert began. The alerting device has an alert signal detector, a timing unit, an alert signal generator and an alert unit. The alert signal detector responds to an activation signal to activate the timing unit, and the alert signal detector responds to a deactivation signal to reset the timing unit. The timing unit generates timing information to the alert signal generator indicating the elapsed time since the occurrence of the activation signal. The alert signal generator responds to the activation signal and to the timing information to generate an alert signal that indicates the elapsed time since the occurrence of the activation signal. The alert signal generator further responds to the deactivation signal to disable the alert signal. The alert unit responds to the alert signal to generate an alert that reflects the elapsed time since the occurrence of the activation signal.

Abstract: A transmission power control scheme for a mobile communication system for suppressing the transmission power to an absolutely necessary minimum level, and increasing the subscriber capacity by reducing an amount of interference. In this scheme, at a time of controlling a transmission power of each radio channel at one of the base station and the mobile station so as to make a difference between a target CIR and a reception CIR of each radio channel at another one of the base station and the mobile station smaller, the target CIR for all radio channels at that another one of the base station and the mobile station are set independently, and/or the target CIR for each radio channel is changed at that another one of the base station and the mobile station, according to a channel quality of each radio channel at either one of the base station and the mobile station.

Abstract: A method for setting up perch channels in a mobile communication by a cellular system, capable of setting up a perch channel and a perch channel list for surrounding base stations at each newly provided base station autonomously. At the newly provided base station, reception levels of signals transmitted by mobile stations to surrounding base stations are measured by scanning uplink control channels corresponding to perch channels, and a perch channel of the newly provided base station and a perch channel list to be signaled by the newly provided base station are autonomously set according to the measured reception levels.

Abstract: In a broadband antenna using a semicircular conductor disc, a semicircular cutout is formed in the semicircular radiator concentrically therewith. Alternatively, a semicircular arcwise radiating conductor with a semicircular cutout defined concentrically therewith is bent into a cylindrical shape to form a radiator.

Abstract: A private mobile communication system serves to support communication between mutual portable or mobile radio telephone equipment which are registered in the system, and communication between the portable or mobile radio telephone equipment and a telephone connected to a public network. A portable or mobile radio telephone equipment which is not registered in the system transmits a request for call to the public network through a private control channel controlling section. A radio base station in the system transfers the request for call transmitted through a private channel to a PBX. The PBX serves to support the call to the public network in response to the request for call transmitted through the private channel.

Abstract: The communication terminal (102) is provided with a notice unit (204) for recognizing a state of use of itself and states of use of the data terminals (103.sub.1) through (103.sub.n) and notifying a result of the recognition to the network side, whereas the network system (101) is provided with a storage unit (303) for registering a communication terminal in which the communication terminal (102) and at least one of the data terminal (103.sub.1) through (103.sub.n) became usable and deleting the registration of the communication terminal (102) or a communication terminal in which the data terminals (103.sub.1) through (103.sub.n) became unusable, in accordance with a result of the notice made by the notice unit (204), so that a receiving possible state of the communication terminal (102) is preliminarily registered on the side of the network system (101). Moreover, the receiving standby state is discriminated between a voice-only standby state and a voice and packet simultaneous standby state.

Abstract: A mobile communication system is provided in which a base station commands a mobile station (or field monitor) to measure the field strength for a specific channel. The mobile station reports the measured results to the base station. The measured results are used in conjunction with base station identification codes to obtain a single representative value which is used to determine what channels can be selected and used by the system. This enables an existing cellular system to be utilized as a first mobile communication system, and makes it possible to construct a second mobile communication system in the same area as the service area of the first system.

Abstract: The present invention relates to an echo canceler for training an echo path estimation without providing a hindrance to a speech. The echo canceler of the present invention includes a pseudo noise generator for generating a certain pseudo noise. This pseudo noise is forcibly supplied to a transmission line for transmitting a far-end talker's voice. Here, in the case where the far-end talker's transmitting speech level is faint or the far-end talker is in a speechless condition, a certain correlation is established between the pseudo noise and a signal of the transmission line for transmitting the near-end talker's voice. Based on such a correlation as just mentioned, a coefficient for generating an echo replica is calculated. Therefore, a training for estimating an echo path is performed based on the pseudo noise and without depending on the far-end talker's voice, thereby enabling to generate an appropriate echo replica.

Abstract: A transmitter receiver implementing both frequency division duplex and time division duplex in one device in a CDMA mobile communication system. In the FDD mode, data in an interleave memory in an interleaver is read at a predetermined read rate V.sub.R =V.sub.N, where V.sub.N is a normal rate. In the TDD mode, a transmitting carrier frequency is set identical to a receiving carrier frequency, and the read rate V.sub.R of the interleave memory and the write rate V.sub.W of the deinterleave memory are set at V.sub.R =V.sub.W >2V.sub.N. The transfer rate V.sub.T from column to column of the memories are set identical in the FDD mode and the TDD mode. This makes it possible to create a vacant duration while transferring from column to column, and to perform reception or transmission during the vacant duration. The remaining operation of the TDD mode is the same as the operation of the FDD mode.

Abstract: A communication method and system which can enlarge the communication capacity using a rather simple system. The communication method and system provides different spreading codes to two signal systems at a receiving station.

Abstract: In a time diversity receiver, where in time diversity is performed using the detector output, without any use of a receiving level detection circuit, thereby simplifying the receiver circuitry and reducing power consumption.

Abstract: A service area expansion scheme for a mobile communication system, capable of efficiently connecting thinly populated areas (satellite zones) to a mobile communication network so as to expand the service area of the mobile communication system economically. In expanding the service area, remote base stations are set at thinly populated areas, while a remote mobile local switching station for connecting the remote base stations to the mobile communication network is provided. The remote base stations and the remote mobile local switching station are selectively connected through the public network by using the respective channel connection units for providing connections with the public network. The remote base stations and the remote mobile local switching station can be replaced by satellite base stations and a satellite mobile local switching station for connecting the satellite base stations to the mobile communication network.

Abstract: A call admission control scheme for a CDMA mobile communication system which can satisfy a given connection quality (blocking probability) while guaranteeing a predetermined communication quality. At each base station, a blocking probability and an outage probability of communication quality at each base station are calculated to adjust a maximum number of simultaneously connectable users at each base station according to the calculated results, and a call admission control is carried out according to the adjusted maximum number of simultaneously connectable users.

Abstract: In a mobile radio communication system wherein, in order to call a receiver from a base station, a paging signal containing address information corresponding to the receiver to be called is transmitted n times, the position of a paging signal that is transmitted for the second or subsequent time is determined, in accordance with a prearranged rule, in relation to the position of the same paging signal when it was transmitted for the first time, and the receiver achieves more efficient battery savings by stopping its receiving operation with respect to signal portions which have been confirmed as having already been received without error. The receiving operation is intermittently stopped at a timing corresponding to identical signal portions of the same repeatedly received paging signal.

Abstract: A transmission power control method in a mobile satellite communication system implementing accurate control of transmission power of a base station by obtaining an average received signal level at a mobile station at high accuracy. The mobile station measures an average received signal level Q.sub.k in a predetermined period (step SP2), and informs the base station of the average received signal level Q.sub.k and an actual measuring time T.sub.k (step SP3). The base station calculates a total measuring time t.sub.k which is the sum total of the actual measuring time T.sub.k (step SP16), a corrected average received signal level R.sub.k associated with the average received signal level during the total measuring time t.sub.k (step SP18), and a measuring error .DELTA.D.sub.k (step SP17), and controls the transmission power on the basis of these values (step SP21). Estimating the measuring error .DELTA.D.sub.k in the total measuring time t.sub.k longer than the individual actual measuring time T.sub.

Abstract: A base station selection scheme for a CDMA cellular system capable of reducing the transmission power of the mobile station and increasing the subscriber capacity, by accounting for the uplink interference power at each base station. An uplink interference level is measured at each base station, while a perch channel is transmitted from each base station to the mobile station, and a perch channel reception level of the perch channel transmitted from each base station is measured at the mobile station. Then, a connection target base station to be connected with the mobile station is selected according to a received SIR (Signal to Interference Ratio) of each base station determined from the perch channel reception level measured at the mobile station and the uplink interference level measured at each base station.

Abstract: A mobile communications system including a plurality of communications networks, each of which has one location register (a home location register or gate location register) and one or more visitor registers. Each of the visitor registers is located in each one of visiting areas for storing information about a communication terminal. The location register stores the number of the visitor register of the visiting area in which the communication terminal is present, and the information about the communication terminal. When the communication terminal moves between the communications networks, the information about the communication terminal is transferred between the location registers. When the communication terminal moves between the visiting areas in the same communications network, the information about the communication terminal is provided from the location register to the visitor register.

Abstract: In a system which transmits the same paging signals a plurality of times through the air by radio waves, paging signals serve to selectively page radio receivers. Base station facilities can be deployed at a comparatively low cost even when there are few customers per service area by variably setting the number of times that the paging signals are transmitted from the base stations.

Abstract: A mobile communication system having a high precision frequency base station device with a high precision frequency generator, and the other low precision frequency base station device with a low precision frequency generator which receives transmission waves from the high precision frequency base station device using a transmission frequency in a prescribed frequency precision, and carries out transmission and reception by controlling transmission and reception frequencies of own station in accordance with the frequency precision of the received transmission waves.

Abstract: Centralized controlling apparatus controls overall flow of signals. Calling apparatus transmits a call signal in response to a call instruction signal transmitted from the centralized controlling apparatus. Information receiving apparatus receives the call signal to transmit an answer signal. Answer receiving apparatus transmits an answer acknowledge signal when it receives the answer signal. The centralized controlling apparatus transmits an information/control signal to information transmitting/distributing apparatus when it receives the answer acknowledge signal. The information transmitting/distributing apparatus distributes the information/control signals to a plurality of information transmitting apparatus. The plurality of information transmitting apparatus transmits simultaneously the information signals to the information receiving apparatus by radio.